Various protection mechanisms for lithium ion batteries exist. If a lithium ion battery overcharges, strong exothermic reactions are possible and the potential for causing a fire increases.
To prevent a lithium ion battery from overcharging, a battery protection circuit is used. The battery protection circuit, an example of which is shown in FIG. 1, often contains, among other components, two FET (field effect transistor) switches 122, 124 and a control IC (integrated circuit) 120. One FET prevents current from flowing into the battery, while the other prevents current from flowing from the battery unless the control IC enables it.
Multi-chip modules containing control ICs and MOSFETs exist. However, a number of improvements could be made. For example, some conventional multi-chip modules contain leads on all four sides of the packages. This results in larger modules, which is undesirable, because such modules are used in small electronic devices such as cell phones. The sizes of the multi-chip modules can be reduced, but this reduces the current carrying capacity of the chips that can be used in such packages.
Thus, improved multi-chip modules are needed.
Embodiments of the invention address the above problems and other problems, individually and collectively.